1. The Field Of The Invention
The present invention relates generally to a method of cleaning printing presses, and, more particularly, to a method of simultaneously cleaning both the press rollers and the blanket cylinder of a printing press.
2. Description of Related Art
In order to maintain high quality printing, it is necessary to periodically clean the rollers and cylinders of a printing press. Since the cleaning process necessarily results in press xe2x80x9cdown time,xe2x80x9d it is highly desirable that the amount of xe2x80x9cdown timexe2x80x9d be minimized while at the same time obtaining effective cleaning and drying of the cylinders.
There are five areas of a printing press: impression, transfer, blanket, plate, water train and ink train. In the past, each of these areas has been heretofore cleaned separate and apart from one another. Various methods have been employed ranging from manual cleaning by a press operator to mechanical means which have been either manually operated or operated in a semi-automatic mode. These various methods have had varying degrees of success measured by amount of time required to thoroughly clean the various areas of the press, materials expended, danger to human limb, amount of volative organic compounds (VOC) released into environment, wear on existing parts/finishes and thoroughness of cleaning
One of the more difficult and time consuming tasks in a printing operation is the need to periodically clean the various printing press rollers and cylinders, such as the blanket cylinder, impression cylinder, plate cylinder and, in particular, the ink rollers (collectively referred to as an xe2x80x9cink roller trainxe2x80x9d) of ink and other debris. These cleaning operations are sometimes referred to by those skilled in the art as xe2x80x9cwashingsxe2x80x9d or xe2x80x9cwashupxe2x80x9d operations. Such washup operations are needed to remove extraneous paper dust, debris, and other contaminants from the ink roller train to improve the quality of the printed product.
The ink roller train is usually cleaned when a printing color is changed or during a pause of a printing operation. Ink roller washings are tedious operations, often requiring significant (and sometimes dangerous) manual intervention on the part of the press operator. The individual rollers of the ink roller train must be separated to access in order to clean all the rollers and cylinders. The separation and cleaning of the roller train could take as long as 20 minutes.
Traditionally, the print operator usually xe2x80x9csquirtsxe2x80x9d or otherwise applies a cleaning solvent directly onto the print cylinders and ink roller train. The solvent loosens the ink and other debris from the cylinders and ink rollers, which is then scraped off or otherwise removed from the printing press. The scraping operation is a messy and time consuming task, and in the past has involved manually wiping the surface of the cylinders and rollers so that the solvent, along with the ink and other solid debris, can be collected in a trough or pan, or alternatively, captured by a rag or some other absorbent material. Therefore, a need exists for an improved and efficient system for cleaning the cylinders of a printing press that reduces clean-up or down time, and reduces the chance of injury to someone assigned to clean the press.
As an alternative to manually cleaning the printing press, the washup operation has been performed by devices designed to engage the cylinders or ink rollers and scrape off the ink or other debris. One such device includes, for example, a cleaning blade adapted to engage the ink roller and scrape debris from the ink rollers into an ink pan. However, it is frequent that the blade is inadequately cleaned following a washup operation and that the geometry of the blade tip is altered with subsequent washings, lowering both the effectiveness of the blade in cleaning the press rollers, and lessening the effective life expectancy of the blade. The disposal of the ink scraped off the roller train and collected in the ink pan is also of concern. The pan must be removed, emptied and cleaned from the next roller train cleaning operation which is a messy operation in itself. Since cloths and a solvent are used to clean the ink pan, operator""s hands are often smeared requiring additional cleanup. Furthermore, because this ink pan cleaning has to be repeated for the cleaning of each roller train, the process is inefficient.
Such tasks are tedious, time consuming and messy, and result in prolonged periods of press downtime while the operator cleans the stained components. As a result of these inconveniences it is often the case that washups are neglected by the operator, causing undue wear to the components and lessening their life expectancy.
Another device includes a cylinder or roller cleaner having an inflatable bladder which fills with air, or other gases, to move a cleaning cloth into engagement with the surface of the cylinder or roller and remove debris. However, the current cylinder or roller devices using an inflatable bladder are constructed and adapted to focus on and clean only one roller at a time, not multiple rollers.
There exists a need, therefore, for a washup device and method for cleaning the blanket cylinders and virtually all rollers in an ink train assembly used in printing machines which facilitates the automation of washings operations while cleaning virtually all the rollers and all cylinders by one system; which is easily retrofitted into existing printing presses without the need for complicated additions; which reduces the amount of volative organic compounds released into the environment; and, which virtually eliminates the down time and effort necessary to clean the cylinders and rollers of the printing press.
3. Summary of the Invention
The present invention solves these and other needs as apparent from the following description. The embodiments of the present invention was developed to clean all the cylinders and rollers of a printing press by automatic means.
One embodiment of the present invention features a blanket cleaner arranged around the blanket cylinder and an ink roller cleaner arranged around one of the ink rollers of the ink roller train, respectively, and a fluid applicator. The fluid applicator is arranged to apply a fluid to at least one ink roller of the ink roller train. Usage of the two cleaners located at appropriate positions within the printing press and application of an appropriate fluid to the ink roller train results in an environmentally friendly cleaning of both the blanket cylinder and the rollers of the ink roller train in a substantially reduced amount of time.
In another embodiment, the cleaners are activated according to a sequence. In the sequence, one of the cleaners can be first activated for a first duration of time. The remaining cleaner is activated for a second duration of time. Finally, the fluid applicator is activated to apply the fluid to the ink roller train for a third duration of time. The duration of time for which each cleaner is activated is variably adjusted as is the sequence of operation of the first and second cleaners and the fluid applicator to substantially clean both the blanket cylinder and the ink roller train.
In a further embodiment, a computerized controller is included to automatically control the sequence of operation and the respective durations of operation for the first and second cleaners and the fluid applicator.
In yet another embodiment, at least one of the cleaners includes a pre-soaked cloth.
The invention also includes the method of cleaning both the blanket cylinder and the ink roller train of a printing press. The method includes activating a blanket cleaner arranged around the blanket cylinder for a first duration of time. An ink roller cleaner arranged around an ink roller of the ink roller train is then activated for a second duration of time. Finally, a fluid spray applicator arranged around an ink roller of the ink roller train is then activated.